The visual system of the goldfish grows throughout life, and is capable of considerable regeneration and restoration of function after damage, the processes of growth and regeneration involving synaptogenesis and a changing pattern of neural connections over time. This project will study visual function during these processes with the aim of a) understanding the normal processing of information (especially spatial) in the retina and optic tectum; b) describing the changing organization of receptive fields; and c) investigating certain mechanisms responsible for the formation and regeneration of visuotopic maps on the optic tectum. Behavioral methods will be used on goldfish of different sizes, and with regenerated retinotectal connections to measure psychophysical thresholds, and spatial and temporal resolution. Electrophysiological recording will also be applied to same ends. Light microscopy will be used to investigate the anatomical basis of receptive field organization in the retina, and autoradiography to trace the central connections established after regeneration.